<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Document</title>
    <style>
      div {
        width: 80px;
      }

      input[type="text"] {
        width: 50px;
        height: 44px;
        outline: none;
        border: 1px solid #ccc;
        text-align: center;
        border-right: 0;
      }

      input[type="button"] {
        height: 24px;
        width: 22px;
        cursor: pointer;
      }

      input {
        float: left;
        border: 1px solid #ccc;
      }
    </style>
  </head>

  <body>
    <div>
      <input type="text" id="total" value="1" readonly />
      <input type="button" value="+" id="add" />
      <input type="button" value="-" id="reduce" disabled />
    </div>
    <script>
      const input = document.querySelector("#total")
      const input2 = document.querySelector("#add")
      const input3 = document.querySelector("#reduce")
      input2.addEventListener("click", () => {
        input.value++
        if (input.value > 1) {
          input3.disabled = false
        }
      })
      input3.addEventListener("click", () => {
        input.value--
        if (input.value <= 1) {
          input3.disabled = true
        }
      })
    </script>
  </body>
</html>
